Area Forecast Discussion
Issued by NWS Goodland, KS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGLD 171908
AFDGLD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
108 PM MDT THU APR 17 2014

.UPDATE...
ISSUED AT 702 AM MDT THU APR 17 2014

PLACED FOG IN FOR THIS MORNING OVER THE NORTHWEST PART OF THE
AREA...MAINLY YUMA COUNTY. FOG SHOULD LIFT IN THE NEXT 2 HOURS OR SO.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 421 AM MDT THU APR 17 2014

FORECAST PROBLEMS WILL BE WINDS THROUGH THE PERIOD AND CHANCE OF
PRECIPITATION LATE IN THE PERIOD. SATELLITE SHOWING A SOMEWHAT
AMPLIFIED BUT STILL PROGRESSIVE FLOW FROM THE PACIFIC THROUGH NORTH
AMERICA. STRONG SYSTEM SYSTEM APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA WITH A RIDGE PUSHING IN AHEAD OF IT. AT THIS TIME
THIS IS LEAVING A NORTHWEST FLOW WITH EMBEDDED SHORTWAVE TROUGHS
OVER THE AREA.

AT JET LEVEL...THE NAM WAS DOING A LITTLE BETTER THAN THE GFS. AT MID
LEVELS...OVERALL THE MODELS WERE NOT TOO FAR APART WOULD HAVE TO
GIVE A SLIGHT EDGE TO THE GFS. HOWEVER WITH THE SYSTEM CURRENTLY
PASSING THROUGH THE REGION...THE ECMWF WAS DOING THE BEST. THE
CANADIAN WAS DOING A LITTLE BETTER THAN THE ECMWF...GFS AND NAM ON
THE SURFACE WIND/PRESSURE FIELD. THE GFS WAS DOING A LITTLE BETTER
THAN THE OTHER OUTPUT IN THE LOW LEVEL THERMAL FIELD.

TODAY/TONIGHT...LEFT FRONT QUADRANT STARTS OUT NEAR THE WESTERN END
OF THE AREA AT THE BEGINNING OF THE DAY AND THEN WILL MOVE ACROSS
THE EASTERN HALF DURING THE AFTERNOON...WHICH MEANS IT WILL BE EAST
OF THE AREA AT THE BEGINNING OF THE NIGHT. UPPER SYSTEM WILL
CONTINUE TO AFFECT THE FAR SOUTHERN PORTION OF THE AREA EARLY THIS
MORNING. BASED ON CURRENT RADAR/OBSERVATIONAL TRENDS...SLIGHT
CHANCE TO LOW CHANCE OF PRECIPITATION IN THE FAR SOUTH LOOKS
REASONABLE AND DID NOT ADJUST.

NEXT BUT MINOR CONCERN WILL BE HOW LONG THE CLOUD COVER WILL LAST
THIS MORNING AND IF THAT WILL AFFECT THE HIGH TEMPERATURES. MODELS
NOT DOING A GOOD JOB WITH THE STRATUS WITH RAP DOING THE BEST AND
WILL CONTINUE TO WATCH IT AND OBSERVATIONAL TRENDS TO MAKE ANY
FURTHER ADJUSTMENTS. AS SYSTEM TO OUR SOUTH PULLS OUT...SHOULD GET
A DECENT AMOUNT OF SUBSIDENCE FROM THAT BUT AS MENTIONED ABOVE THE
UPPER JET IS NOT YET TO OUR EAST. DUE TO THE LINGERING CLOUD COVER
AND UNFAVORABLE SURFACE WINDS...ESPECIALLY IN THE EASTERN PORTION...
WILL NOT GET TOO EXCITED ABOUT WARMING TEMPERATURES AND STUCK CLOSE
TO THE PREVIOUS FORECAST.

IF SKY COVER CLEARS AS THE MODELS THINK AND THE GRADIENT
TIGHTENS/PRESSURE FALLS OCCUR AS SURFACE HIGH MOVES EAST AND THE
LEE TROUGH DEVELOPS...WINDS SHOULD GET AT LEAST BREEZY IN THE
WESTERN HALF MAYBE EVEN WINDY. NO HIGHLIGHT WILL BE NEEDED. WINDS
WILL STAY UP TONIGHT AS WARM AIR ADVECTION KICKS IN. MINS WILL BE
WARMER AND MAY NEED TO BE WARMED UP MORE FROM WHAT I HAVE THEM.

FRIDAY/FRIDAY NIGHT...RIDGING ALOFT MOVES IN/THROUGH IN THE FIRST
HALF OF THE DAY WITH FLOW ALOFT TRANSITIONING TO SOUTHWEST IN THE
AFTERNOON. WARMER 850 MB TEMPERATURES AND PLENTY OF SUN WILL ALLOW
FOR A GOOD WARMUP. TENDED TO FOLLOW THE WARMER GUIDANCE.

HOWEVER...THE BIGGER STORY WILL BE THE INCREASING WINDS. GRADIENT
AND 3 HOUR PRESSURE FALLS ARE TIGHTER/LARGER THAN FOR TODAY SO WILL
DEFINITELY SEE A WINDY DAY. SOME OF THE GUIDANCE WOULD SAY WIND
SPEEDS WILL GET NEAR WIND ADVISORY CRITERIA. THIS WILL BE POSSIBLE
DUE TO THE SOUTHWEST FLOW ALOFT DEVELOPING AHEAD OF OUR NEXT STORM
SYSTEM THAT IS MOVING INTO THE DESERT SOUTHWEST. DAY SHIFT WILL
NEED TO LOOK AT THIS CLOSELY AGAIN TO NOT ONLY INCREASE SPEEDS BUT
ALSO AT A POSSIBLE WIND ADVISORY.

LACK OF INSTABILITY AND AN EXTREMELY DEEP DRY LAYER IN THE LOWER
LEVELS OF THE ATMOSPHERE WILL KEEP PRECIPITATION FROM DEVELOPING OR
REACHING THE GROUND DURING THE NIGHT. NO UPPER JET IS CLOSE AND NO
LOW LEVEL JET LOOKS TO BE IN THE AREA. SO REMOVED THE SLIGHT CHANCE
OF PRECIPITATION FROM THE NIGHTTIME PERIOD. WITH WARM AIR AND SOME
MOISTURE ADVECTION STRATUS AND MAYBE SOME FOG MAY DEVELOP/MOVE INTO
THE AREA. SINCE ONLY THE NAM IS SHOWING IT AND THE 06Z NAM PULLED
BACK FROM EARLIER SOLUTION...WILL NOT INCLUDE ANY FOG BUT THE DAY
SHIFT WILL NEED TO TAKE ANOTHER LOOK.

SATURDAY/SATURDAY NIGHT...SPLIT FLOW WILL BE OVER THE AREA THROUGH
THIS PERIOD. THIS IS LEADING TO MAJOR DIFFERENCES IN HOW THE
MODELS HANDLE THE POSITION OF FEATURES AT ALL LEVELS ACROSS THE
AREA. OVERALL THE DETERMINISTIC MODEL CONSENSUS AND ENSEMBLES WERE
SIDING MORE WITH A SLOWER ARRIVING AND FURTHER SOUTHWEST UPPER
TROUGH MOVING IN AND THROUGH THE AREA DURING THIS PERIOD. HOW THE
DETERMINISTIC OUTPUT HANDLED THE MID/UPPER LEVELS AFFECTED HOW
FAST THEY MOVED IN THE FRONT WITH A SIMILAR CONSENSUS AS WHAT WAS
SHOWN FOR THE UPPER LEVELS. THE 06Z NAM SLOWED DOWN FROM THE 00Z
RUN AND MORE CLOSELY RESEMBLED THE ECMWF AND CANADIAN WHICH LOOKED TO
BE HANDLING THE BEHAVIOR OF THE LEE SIDE TROUGH BETTER THAN
EVERYBODY ELSE.

SO DUE TO THE MODEL TRENDS AND ENSEMBLES...SIDED WITH THE SLOWER
AND FURTHER SOUTHWEST UPPER SOLUTION. SO THIS MEANT I PREFERRED
THE SLOWER/FURTHER WEST FRONTAL POSITION FOR THE DAY. SO AHEAD OF
THE FRONT...MOSTLY IN THE SOUTHEAST PORTION...BREEZY TO WINDY
CONDITIONS WILL ONCE AGAIN OCCUR. MORE IMPORTANTLY THE FRONTAL
POSITION WILL DETERMINE WHERE THE BEST CHANCE OF PRECIPITATION WILL
BE. IN ADDITION TO THAT...THE MODELS...DESPITE THE FRONT...TENDED
TO CAP THE LOW LEVELS WITH THE NORTHWEST HALF HAVING THE LEAST AMOUNT
OF CAP. SO BASED ON THE CAP...AND A FURTHER WEST FRONTAL POSITION...
I REDUCED THE CHANCE OF PRECIPITATION AND PUT THE HIGHEST POPS IN
THE NORTHWEST AND CENTRAL POSITION WHERE THE BOUNDARY/BEST LOW LEVEL
CONVERGENCE IS AND WHERE THE CAP IS WEAKEST. ALSO CLOUD COVER IN
ADVANCE OF THIS SYSTEM COULD INHIBIT HEATING AND EXPECTED
INSTABILITY.

TEMPERATURES WILL BE TRICKY DUE TO THE UNCERTAINTY OF THE FRONTAL
POSITION AND ALSO THE AMOUNT OF CLOUD COVER IN ADVANCE OF THE UPPER
STORM SYSTEM. MODELS TENDED TO BE WARMER...ESPECIALLY AHEAD OF THE
FRONT. HOWEVER...DID NOT GO AS WARM AS I COULD DUE TO THE CLOUD
COVER.

BEST TIME FOR PRECIPITATION LOOKS TO ARRIVE DURING THE NIGHT. THE
DEEPEST LIFT ARRIVES DURING THAT TIME AND THE DETERMINISTIC QPF
OUTPUT AND ENSEMBLE PRECIPITATION PROBABILITIES AGREE WITH THAT.
THE SOUTHEAST HALF LOOKS TO HAVE THE BEST CHANCE. SO LEFT THE
PRECIPITATION FORECAST FOR THE NIGHT ALONE. SOMETHING TO WATCH FOR
ONCE THUNDERSTORMS DEVELOP. STORM MOVEMENTS WILL BE SLOW AND NEARLY
PARALLEL TO THE FRONT. SO THERE WILL BE POTENTIAL FOR TRAINING AND
HEAVY RAINFALL.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 1252 PM MDT THU APR 17 2014

SOUTHERN STREAM SHORTWAVE TROUGH WILL APPROACH THE AREA
SATURDAY AFTERNOON. COLD FRONT FORECAST TO BE NEAR A NORTON TO
TRIBUNE LINE WILL BE THE MOST LIKELY AREA FOR CONVECTIVE
INITIATION. SBCAPE AXIS OF UP TO 1500 J/KG WILL BE IN PLACE ALONG
AND EAST OF THE FRONT WITH AFTERNOON TEMPERATURES WELL INTO THE
80S. DEEP LAYER SHEAR OF 20-30KTS IS FORECAST FOR THAT AREA. THOSE
PARAMETERS ONLY MARGINALLY SUPPORTIVE OF SEVERE STORMS BUT STILL
COULD SEE SOME SMALL HAIL POSSIBLY UP TO QUARTER SIZE WITH
STRONGER UPDRAFTS. MORE SHOWERS/ISOLATED THUNDERSTORMS WILL
DEVELOP IN THE POST FRONTAL UPSLOPE ENVIRONMENT SATURDAY NIGHT AS
MAIN SYNOPTIC SCALE FORCING ARRIVES. MODELS SHOW SCATTERED SHOWERS
AND ISOLATED THUNDER LINGERING INTO SUNDAY WITH COLDER AIR ALOFT
ASSOCIATED WITH THE UPPER SHORTWAVE...BUT INSTABILITY WILL BE
VERY LIMITED BY THAT TIME SO NOTHING SEVERE. HIGH TEMPERATURES ON
SUNDAY WILL BE AROUND 70.

UPPER RIDGE WILL REBUILD FOR EARLY NEXT WEEK. WARMING SURFACE
TEMPERATURES AND UPSLOPE FLOW INTO COLORADO WILL CONTRIBUTE TO
ISOLATED AFTERNOON/EARLY EVENING STORMS DESPITE LACK OF UPPER
LEVEL FORCING. ACTIVITY WILL BE DIURNAL IN NATURE...QUICKLY
DISSIPATING AFTER SUNSET. NEXT SHORTWAVE TROUGH WILL ARRIVE ON
WEDNESDAY BUT MODELS INDICATE MOST OF THE LOCAL AREA WILL GET DRY
SLOTTED. HOWEVER...DRY LINE WILL BE NEAR THE FAR EASTERN COUNTIES
AND THEY STAND THE BEST CHANCES OF GETTING THUNDERSTORMS WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT. UPPER TROUGH AXIS WILL STILL BE
NEARBY ON THURSDAY SO HARD TO RULE OUT AN ISOLATED SHOWER OR
THUNDERSTORM THOUGH INSTABILITY AXIS WILL BE FAR EAST BY THAT
TIME. TEMPERATURES MONDAY THROUGH WEDNESDAY WILL BE ABOVE TO MUCH
ABOVE NORMAL THEN NEAR NORMAL ON THURSDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1125 AM MDT THU APR 17 2014

MORNING STRATUS IS RAPIDLY BURNING OFF. STRATUS HAS CLEARED KMCK
AND SHOULD CLEAR KGLD WITHIN THE NEXT 1-2 HOURS. SOUTH WINDS INCREASE
THIS AFTERNOON AND REMAIN ELEVATED THROUGHOUT THE TAF CYCLE...
ESPECIALLY AT KGLD. FORECAST GUIDANCE INDICATES ANOTHER ROUND OF
STRATUS IS POSSIBLE TOMORROW MORNING AS MOISTURE RETURN INCREASES.
FOR NOW...HAVE PLACED A SCT MVFR GROUP IN TAF FOR KGLD AND FEW
MVFR GROUP FOR KMCK. THE MAJORITY OF THE STRATUS SHOULD STAY
SOUTH. SOUTH WINDS BECOME GUSTY DURING THE LATE MORNING TOMORROW
AS A LEE TROUGH STRENGTHENS ALONG THE FRONT RANGE.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...024
AVIATION...RRH




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.